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Flat adenomas exist in asymptomatic people: important implications for colorectal cancer screening programmes
1Gastroenterology Unit, Leicester General Hospital, UK.
Gut
|April 6, 1999
Summary
Flat adenomas, which can progress to cancer, were found in asymptomatic individuals screened via flexible sigmoidoscopy. This discovery highlights the need for improved detection methods for these colorectal cancer precursors.
Area of Science:
- Gastroenterology
- Colorectal Cancer Research
- Endoscopy
Background:
- Flat adenomas are non-exophytic colorectal lesions with a high potential for severe dysplasia and rapid progression.
- Previously, flat adenomas had not been documented in a British asymptomatic population.
Purpose of the Study:
- To investigate the prevalence of flat adenomas in an asymptomatic population undergoing colorectal cancer screening.
- To assess the characteristics and potential for malignancy of these lesions.
Main Methods:
- A large randomized controlled trial involving 3000 asymptomatic subjects (aged 55-64) utilized flexible sigmoidoscopy for screening.
- All detected polyps were surgically removed and histologically examined to identify flat adenomas.
Main Results:
- Four flat lesions were identified in three subjects, indicating a prevalence of one per 1000 screened individuals.
- Three lesions showed severe dysplasia, and one contained adenocarcinoma; three were under 5 mm, and one was 15 mm.
Conclusions:
- Flat adenomas with severe dysplasia are present in the asymptomatic population.
- Gastroenterologists require training to effectively identify these lesions.
- The findings are significant for research into colorectal cancer etiology and epidemiology.
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